In recent years, a large amount of heat is generated at a time of an operation of an electronic device due to miniaturization or a high integration of an electronic device, such as by LSI or the like. Therefore, means for cooling an electronic device efficiently are proposed. For example, it is proposed that a water cooling type cooling device is used, because it is not possible to dissipate a large amount of heat by merely attaching a heat sink to an electronic device such as an LSI, to be air-cooled.
A general water cooling type cooling device is a cooling device for passing a refrigerant (a cooling water) through a closed heat sink referred to as a “water jacket” to be cooled. In particular, a microchannel cooling device among water cooling type cooling devices has a high cooling performance and is promising for cooling an LSI.
On the other hand, it is also proposed that thermal energy generated by an electronic device such as an LSI is recovered and reused as an electric power in order to attain energy saving in an electronic instrument. A thermoelectric element is frequently used in order to recover thermal energy as an electric power. A thermoelectric element is arranged between an LSI and a heat sink and a temperature difference between the LSI and the heat sink is applied to the thermoelectric element, so that the thermoelectric element generates an electric power. Alternatively, it is also proposed that a heat conductive member is drawn from an LSI that is a heating part and connected to a high temperature side of a thermoelectric element and a heat sink is connected to a low temperature side of the thermoelectric element so that a temperature difference is applied to the thermoelectric element and the thermoelectric element generates an electric power.
In order to utilize a temperature difference between a water cooling device for passing a refrigerant (a cooling water) through a conventional closed heat sink referred to as a “water jacket” to be cooled and an electronic component that is a heating part, it is necessary to connect a low temperature side of the thermoelectric element to the heat sink thermally and to connect a higher temperature side thereof to the electronic component thermally. For a configuration for inserting a thermoelectric component between a heat sink and an electronic component, a heat resistance of the thermoelectric element is high, so that it is not possible to transfer heat of the electronic component to the heat sink efficiently and it is not possible to cool the electronic component efficiently. Accordingly, cooling of an electronic component may be insufficient, because a thermoelectric element is provided, and a temperature of the electronic component may be high.
Furthermore, in a case where a heat conductive member is drawn from an electronic component as a heating part and connected to a high temperature side of a thermoelectric element, the heat conductive member is at a temperature of the electric component that has already been cooled, so that a temperature of the heat conductive member is not sufficiently high and it is not possible to obtain a large temperature difference. Because an amount of an electric power generated by a thermoelectric element is proportional to an applied temperature difference, an electric power capable of being generated by the thermoelectric element is small and an efficiency of recovery of energy is low.
Patent Document 1: Japanese Patent Application Publication No. 2001-282396
Patent Document 2: Japanese Patent Application Publication No. 2003-269817